The present invention relates to computerized analysis of control processes and in particular to a program working with computerized process simulations to identify energy savings.
The manufacture of many products requires the execution of complex processes typically under automated control. Such processes, including diverse processes such as oil refining, paper manufacture, synthesis of pharmaceuticals, electrical energy generation and the like, may be defined by a set of input and output material streams and input and output energy flows into and out of the process. The process may include multiple unit operations each with corresponding material streams and energy flows.
The complexity of many commercially important processes has led to the development of sophisticated simulation tools in which the streams and flows are characterized numerically and the operations on the streams modeled mathematically so that the proper operation of the process may be verified or modified before actual construction or modification. Commercial products for such simulation include, for example, AspenPlus, a process simulation software package commercially available from AspenTech of Burlington, Mass. and a similar product line commercially available from Intelligen Inc. of Scotch Plains N.J. as well as products manufactured by Pavilion Technologies of Austin, Tex.
While complex processes may be accurately simulated, optimization of the process for particular goals, for example, energy savings and cost is not inherent in the ability to simulate the process. Even when a simulation can reveal how a cost and energy savings may change with changes in the defined streams and flows, particularly for complex processes, the ability to simulate the process alone does not necessarily indicate the type or amount of modifications necessary to optimize an arbitrary parameter. For example, an accurate simulation of a process combining two chemicals in chemical reaction may indicate how the resulting product will change with changes in the input streams of the chemicals but will not necessarily suggest, for example, the introduction of an enzyme that may improve the reaction efficiency or how to change input streams to reduce energy usage. Even trial and error changes to one stream or flow to indicate how it changes energy may not reveal the correct setting for the stream or flow for global energy reduction in the process because of the problem of local minima.
Experts in process control can often identify improvements in a process's efficiency on a case-by-case basis, but software tools to assist non-experts in process optimization or to augment the abilities of experts remain elusive because of the complexity of the problem and the case-by-case nature of the solutions.